Calculate zaqar mongo from mongodb_node_ips
Calculate zaqar mongo from mongodb_node_ips

In order to make the zaqar service fully composable, the mongo ips need
to be calculated without assuming that mongo and zaqar are on the same
node.

Change-Id: I0b077e85ba5fcd9fdfd33956cf33ce2403fcb088

openstack/puppet-tripleo,openstack/puppet-tripleo,openstack/puppet-tripleo